Electromotive drive system, especially a power window drive system for a motor vehicle

ABSTRACT

An electric motor drive mechanism, in particular a window control drive mechanism for a motor vehicle, has an electric motor ( 10 ), which has a motor armature shaft ( 12 ) that is operatively connected to a gear unit ( 14 ) surrounded by a gear housing ( 16 ), and also has a motor electronics unit ( 18 ) surrounded by an electronic housing ( 20 ). The electronics housing ( 20 ) has a guide rail ( 22 ), extending radially to the motor armature shaft ( 12 ), for insertion of the electronics housing ( 20 ) via a counterpart guide ( 23 ) disposed on the gear housing ( 16 ).

PRIOR ART

The invention relates to an electric motor drive mechanism, inparticular a window control drive mechanism for a motor vehicle.Electric motor drive mechanisms are widely known and can be usedespecially in the automotive field for adjusting manifold vehiclecomponents. This applies for instance to adjusting vehicle seats,windows and sun roofs, or also to adjusting mirrors. The drivemechanisms employed as a rule have an electric motor and a gearfollowing it, as well as an electronic control and supply unit. Thiselectronic unit is constructed on a circuit board that is accommodatedin an electronics housing.

To determine position parameters of the actuating drive, sensor devicesthat are disposed on a sensor prong are typically used. These sensordevices interact with the rotating motor armature shaft and count therevolutions of the shaft. For this purpose, it is necessary that thesensor prong and the electronics connected to it be positionable asprecisely as possible and fixable as securely as possible.

These two requirements make for a considerable outlay for assembly ofthe electronics, since by the previous assembly technology all theelectronics along with the sensor device, and optionally in the brushholder, are screwed or clipped to the gear housing. The electronic unitis open toward the gear, so that in addition to the problem ofpositioning and fixation, a sealing problem arises.

ADVANTAGES OF THE INVENTION

The electric motor drive mechanism according to the invention has theadvantage that the electronics housing can be connected to the drivemechanism securely and largely without play; the assembly is simplifiedsubstantially because the electronics housing need merely be slippedonto the guide rail of the gear housing, and exact positioning of thesensor device connected to the electronic unit, for determining positionparameters of the drive mechanism, is made possible.

Advantageous refinements of the electric motor drive mechanism arepossible.

For instance, it is advantageous if the guide rail, which is disposedeither on the electronics housing or on the gear housing, extendssubstantially over the width of the electronics housing. As a result,binding of the electronics housing to the drive mechanism occurs overthe maximum possible length; the electronic unit is optimally fixed, anda sensor prong attached to it can be positioned with high precision.

It is highly advantageous if the guide rail is embodied in rectangularshape. As a result, an ideal positive engagement with the counterpartguide and high strength of the electronics housing, both in thedirection parallel to the motor armature shaft and in the radialdirection, are achieved.

Along with this optimal guidance, which makes close productiontolerances possible, assembly of the electronic unit is facilitatedconsiderably, since it need merely be inserted into the drive mechanismvia this guide mechanism.

A further advantage is that the electronics housing is already guidedbefore the sensor prong dips into the recess of the brush holder. Thisadditionally facilitates assembly of the electronic unit, and at thesame time the risk of damage to the sensor device is minimized.

In a further advantageous feature of the electric motor drive mechanism,the guide rail has at least one central indentation, extending along theguide rail, in which indentation an also central, longitudinallyextending protuberance of the counterpart guide is guided. This featureincreases the precision of the guidance still further.

It is also advantageous if the inserted electronics housing can besecured with a securing means, in particular in the form of a screw.This is preferably disposed on the end of the guide rail remote from themotor armature shaft, at an angle of approximately 45° to the motorarmature shaft. As a result, not only can the play in the radialdirection to the motor armature shaft axis be minimized—as inconventionally. disposed securing means at an angle of 90° to the motorarmature shaft—in addition to the fixation in this radial direction, butat the same time a play-free fastening in the axial direction is madepossible.

A further feature of the invention provides that the electronics housingis braced, opposite a pole pot of the electric motor, with a support pindisposed on the electronics housing. This support pin is received by arecess that is disposed in the brush holder, for instance, and offers anadditional bracing option for the electronics housing. It thereforerelieves the guide mechanism and furthermore minimizes the introductionof force into the sensor prong.

If this support pin has a chamfer, then the precise introduction of thesupport pin into the recess is facilitated.

A quite general advantage of the electric motor drive mechanismaccording to the invention is that the electronic unit is a completelyseparate part, which can be slipped onto various drive mechanismsuniversally. Because of the advantageous guide mechanism, a high degreeof flexibility is achieved, since drive mechanisms and electronic unitsof the most various types can be combined with one another in afundamentally arbitrary way. At little engineering effort or expense,along with substantially simpler assembly, better fixation of theelectronics housing to the drive mechanism and a substantiallymore-precise positioning of the sensor prong, attached to theelectronics housing, to the armature shaft of the drive mechanism areachieved.

DRAWINGS

In the drawing, one exemplary embodiment of an electric motor drivemechanism according to the invention is shown, and it is described infurther detail in the ensuing description.

Shown are:

FIG. 1, a schematic illustration of a fully assembled electric motordrive mechanism;

FIG. 2, the drive mechanism of FIG. 1 with the electronic unit not yetmounted; and

FIG. 3, a section taken along the line I—I of FIG.

DESCRIPTION OF THE EXEMPLARY EMBODIMENT

The exemplary embodiment shown in FIG. 1 has an electric motor drivemechanism according to the invention, in particular a window controldrive mechanism for a motor vehicle, with an electric motor 10 that issurrounded by a pole pot 11 and that has a motor armature shaft 12. Themotor armature shaft 12 is represented only symbolically by a dashedline that indicates its course. The drive mechanism further includes agear unit 14, which is surrounded by a gear housing 16 and is providedwith three bores 15 for mounting purposes. The electric motor 10 isoperatively connected to the gear unit 14 via the motor armature shaft12.

For supply and control of the electric motor drive mechanism, a motorelectronics unit 18 is provided, which is accommodated in an electronicshousing 20.

The electronics housing 20 is solidly joined to the gear housing 16 viaa guide mechanism 22, 23 and is fixed in its position with a securingmeans 24 in the form of a screw. The securing means 24 is screwed intothe gear housing 16 at an angle of 45° to the axis of the motor armatureshaft, on the end of the guide mechanism 22, 23 remote from the drivemechanism. For connection to the electronics housing 20, the securingmeans also passes through a connecting part 26 and thus secures theelectronics housing 20.

A support pin on the side of the electronics housing 20 toward the polepot 11 assures additional bracing of the electronic unit 18 relative tothe pole pot 11. This support pin 28 protrudes into a recess 30 of thebrush holder 32, and thus additional forces in the Z and Y directionsshown are absorbed.

The support pin 28 has a chamfer 34, which makes it easier to introducethe support pin 28 into a recess 30 of the brush holder 32.

Also shown is a sensor prong 36, which protrudes into a second recess 33of the brush holder 32. A sensor device 38 shown in FIG. 2 is disposedon this sensor prong 36 and serves to ascertain position data of themotor.

FIG. 2 shows the exemplary embodiment of FIG. 1, but here the electronicunit 18 is not mounted. This makes it possible to show and describe theguide mechanism 22, 23 and the sensor. device 38 in greater detail.

In FIG. 2 as in the following figures, the same characteristics areidentified by the same reference numerals.

The exemplary embodiment as shown in FIG. 2 explicitly shows the guidemechanism 22, 23, with which the motor electronics unit 18 is slippedonto the drive mechanism. It comprises a guide rail 22, which isdisposed on the electronics housing 20, as well as a counterpart guide23, which is disposed on the gear housing 16. The guide rail 22 and thecounterpart guide 23 are adapted to one another in shape and enable bothexact guidance and secure fixation of the electronics housing 20.

Also visible in FIG. 2 is the sensor prong 36, which on its free end isprovided with a sensor device, which in this exemplary embodiment isembodied as a Hall IC. In the mounted state, this Hall IC interacts witha ring magnet, not shown, that is mounted on the motor armature shaft12. This interaction furnishes position signals for determining theposition of the armature shaft 12, or of the adjustable part connectedto the drive mechanism.

FIG. 3 shows the geometric shape of the guide mechanism comprising theguide rail 22 and counterpart guide 23. The guide rail 22 is embodied inrectangular form; it has two L-shaped struts 44.1 and 44.2, which partlyembrace the counterpart guide of the gear housing 16. Optimal positiveengagement is assured whenever—as shown in the exemplary embodiment—thecounterpart guide 23 is embodied substantially in the form of a T. Thenthe electronics housing 20 connected to the guide rail 23 is ideallybraced both in the X direction shown and in the Y direction.

The bracing and strength of the electronics housing 20 are additionallyenhanced by an indentation 40 in the guide rail 22, into whichindentation a protuberance 412 of the counterpart guide 23 protrudes.

Independently of the exemplary embodiment described, fundamentally othergeometric shapes are also conceivable for the guide mechanism accordingto the invention; the sole decisive factors are the secure guidance ofthe electronics housing 20 and its optimal attachment to the electricmotor drive mechanism, along with the most precise possiblepositionability of the sensor device 38.

What is claimed is:
 1. An electric motor drive mechanism, in particulara window control drive mechanism for a motor vehicle, comprising anelectric motor (10) having a motor armature shaft (12), wherein saidmotor armature shaft (12) is operatively connected to a gear unit (14),said gear unit (14) surrounded by a gear housing (16), said electricmotor drive mechanism further comprising a motor electronics unit (18),said motor electronics unit surrounded by a separable electronicshousing (20), wherein the electronics housing (20) has a guide rail(22), said guide rail (22) extending perpendicularly to the motorarmature shaft (12), said gear housing having a counterpart guide forinsertion of the electronics housing (20).
 2. The electric motor drivemechanism of claim 1, wherein the guide rail (22) and the counterpartguide (23) extend over the width of the electronics housing (20).
 3. Theelectric motor drive mechanism of claim 1, wherein the guide rail (22)has a rectangular shape.
 4. The electric motor drive mechanism of claim1, wherein the guide rail (22) has at least one central indentation(40), extending along the guide rail (22), wherein said counterpartguide has a central, longitudinally extending protuberance (42), andwherein said central, longitudinally extending protuberance (42) isguided In said at least one central indentation (40).
 5. The electricmotor drive mechanism of claim 1, wherein the inserted electronicshousing (20) is secured with a securing means (24).
 6. The electricmotor drive mechanism of claim 5, wherein the securing means is disposedon an end of the guide rail (22) remote from the motor armature shaft(12), at an angle of approximately 45° to the motor armature shaft (12).7. The electric drive mechanism of claim 1, wherein the electronicshousing has a support pin and wherein said electric motor (10) has apole pot (11), and wherein the electronics housing (20) is bracedopposite the pole pot (11) with the support pin (28).
 8. The electricmotor drive mechanism of claim 7, further comprising a brush holder (32)having a recess, and wherein the support pin (28) protrudes into therecess (30) of the brush holder (32).
 9. The electric motor drivemechanism of claim 8, wherein the support pin (28) has a chamfer (34).